5pOiNtSLOW

I don't know jack-shit about AC systems in cars and was in-fact going to just remove everything when I did the efi to carb swap. But, that plan is effectively out the window since summer got here and I realize that there is no way in hell I can go without AC.

My AC is blowing warm air, but I can confirm that certain parts are working.

For instance, the high side plumbing after the compressor is hot... very hot when the AC is turned on, the condenser and orafice tube/ liquid plumbing is all connected and working since that whole length of piping gets freezing cold while the AC is running. So cold that it gets a frozen over ice crust around it.

So, that is right where it goes into the firewall. I can also confirm that the blower motor under the glove compartment is working.

Knowing all of this, my guess is the evaporator is the weak link. I can get one from LRS and have it shipped by Monday for $120.... plus shipping.

I believe the system has already been converted to r134 type refridgerant so a cheaper starting point would be to try to charge the system first.

I'm gonna do that today, but does everything I have written here have any of you guys thinking the same as me? Or am I obviously missing something simple?

Thanks to whoever replies.
Chris

harold harper

it sounds like the orfice tube is clogged.its mybe time for a new dryer and a/c pump.let me know if you need help fixing the a/c.i know every part of that car.by the way all the a/c stuff on the car was from a mark 7.

5pOiNtSLOW

I might need a hand for sure.... I'm gonna definitely give it a shot on my own first, but I'll be damned if I pay some AC shop a ton of money to do the job.

I just read up on a bunch of articles, with pics. Looks like no fun having to take the steering column and dash out just to even get at the AC stuff up under there.

5pOiNtSLOW

Wait, so all of the under-dash stuff is from a Mark VII? How did it all bolt right up?

If I order a new evaporator, for a Mustang, will it be a direct replacement?

fuelie327

did you put a set of gauges on it ? Whats the hi side reading ? A clogged o tube will be a real high high side pressure and low on the low side . It 'll usually suck down on the low side if you rev the engine with a clogged o tube liquid line

5pOiNtSLOW

I need to go get the gauges.... where is the best place to find those?

Zman

I believe Harold meant the stuff in the engine bay is Mark VII, under the dash is Mustang.

5pOiNtSLOW

Yeah, I figured it had to be Mustang stuff under the dash.

I think the problem is under the dash.... something is making the liquid side plumbing turn iced over. It's freezing cold before the firewall... and no water is dripping out of the drain hole.

5pOiNtSLOW

Been thinking about this, and I searched a little more and found this:



So, sounds about right.

GNs-r-slow

Find someone with a set of gauges and a vacum pump. When you change out the parts do yourself a favor and pull a vacum on it. This does a couple things...checks for leaks and gets the trash out of the sytem. Dont keep running it till you fix it or your gonna tras the compressor.
Im sure someone is gonna say you dont need to it will work without it, will it work probably so. It will make a difference in cold air and freeze you ass out cold air or if you have a leak, howlong it will stay cold for